The present invention relates to weighing of hospital beds and other loads supported on wheels or casters.
A basic method for weighing a hospital bed requires that the entire bed be rolled onto a stationary scale platform flush with a floor. This method limits the weighing to one or a few locations in a hospital, which makes weighing inconvenient. Moreover, the scale installation is very expensive.
It is also known to use load cell units placed on top of the floor, and to transfer the load on each leg of the bed to the load cell units by means of special weighing supports, which are arranged to be lowered onto the load cell units for weighing, for instance by retracting the casters. This method makes weighing in each hospital room possible, but the use of special weighing supports on the legs require special and more expensive beds.
It is also possible to use load cell units placed on top of the floor in conjunction with ramps placed on the floor next to the load cell units, so the wheels can be rolled from the floor onto the load cell units via the ramps. For accurate weighing it is, however, necessary to avoid force shunting past the load cell units, so the operator must assure that all four wheels under the bed are transferred fully from the ramps to the load cells, and that no active part of any load cell unit touches the ramps during weighing. The ramps add considerably to the space required for the weighing system, and heavy effort is required to roll the casters uphill on the ramps.